When displaying an image or a video there is a minimum amount of bits needed to be able to display the image/video without a degradation in quality. Since thin lines are visually sensitive to human eyes, and if less number of bits than required are allocated, the image quality is degraded and human eyes will perceive the degradation.
In order to detect visually sensitive parts of an image, previous methods have attempted to detect the existence of edges. However, edge information is difficult to detect for thin lines, and they are almost impossible to obtain if the lines and their backgrounds do not have significant pixel value differences. Also, edge-based detection suffers from vulnerability to noise and other image content in the background.